This invention relates generally to water dispensers for feeding small animals, and more particularly to an improved type thereof specifically adapted for feeding mice and rats.
Automatic feeding of drinking water to experimental animals is essential for labor-saving breeding of these animals and for providing a supply of drinking water at all times.
Among water dispensers for various small animals and birds, those for the mice and rats are technically most retarded, and very few of the devices proposed heretofore have been acceptable for general use. The reason for this is that a large number of water dispensers are required since mice and rats constitute a majority of the experimental animals. This requirement inevitably necessitates a simplified construction of water dispensers which can be produced at a substantially low cost.
Despite this necessity for low-cost construction, however, requirements such as prevention of water leakage, sterile state of the water dispenser, and provision of sensitivity in operation are more strict than those for the water dispensers for other animals and birds. These requirements arise from the requirement that the care of these animals be almost completely free of labor such as bed cleaning and drying and the requirement that the drinking water be readily supplied upon application of a weak nudging force of the mice and rats against a part of the water dispenser but can be instantaneously stopped upon removal of the same force with some amount of the water always kept in a part of the dispenser so that the animal can easily find the part to be nudged.
A further problem arises from the fact that, in the most successful water dispensers of the instant character known heretofore, at least one vital part is made of a flexible, elastic material such as a synthetic rubber. In the operation of the dispenser, this elastic part is called upon to undergo a large number of repeated deflections and deformations due to repeated stress, which will give rise to deterioration of the elastic property of the material if it is not elastically reinforced. Furthermore, all parts of the water dispenser must be periodically sterilized at high temperature and pressure, most conveniently with steam. This further hastens the deterioration of the elastic material.